barnay



A. BARNAY SYSTEM FOR TRANSMITTING ELECTRICAL IMPULSES April 5,1927; I1,623,714

Filed June 4, 1925 3 Sheets-Sheet 2 April v5, 1927. I

1,623,714 A. BARNAY I SYSTEM FOR TRANSMITTING ELECTRICAL IMPULSE$ Fil edJune 4, 192's 3 Sheetsl Sheet s I R 555 may we e Apr. 5, 1927.

UNITED STATES PATENT. orl-lcs.

ANTOINE BARRAY, OI PARIS, FRANCE.

SYSTEM FOR TRANSMITTING ELECTRICAL IMPULSES.

Application filed June 4, 1825, Serial No. 84,892, and in France June11, 1924.

The object of the present invention is a system for transmittingelectrical impulses, which is suitable more particularly in automatictelephone systems, and generally in all step by step switching systems.

The invention concerns automatic switchin s stems in which theconnection is establis e by means of electrical impulses sent over thetwo wires of the calling line in series.

I In systems of this kind, the impulsing circuit, including the callingstation, is es-' tablished progressively until the last organ used forestablishing the connection is operated. As a resultof this, in order tomaintain all of the switches excepting the last intheir operatedpositions, a second holding circuit is required.

Means have been provided for eliminating.

this second circuit for inter-ofiice trunks in automatic telephonesystems, by the addition in these trunks ofan lmpulse repeater which hasthe same function in respect to the sec ond ofiice, as the im ulsesending device of the calling station as to the originating ofiice. 7

One, of. the objects of the present invention is the'suppression ofimpulse repeaters.

With this end in view. the invention con- 0 sists of means em loyed forusing one of the line wires for t e impulsing circuit, and the other formaintaining and controlling the impulsing circuit.

These means are characterized in that the 85 circuit of the callingstation is closed in series with a relay whose function is to produce:

1st. Impulses in a circuit comprising one of the line conductors and in.each of the 40 serially related selector switches, a relay whosefunction is to control the operation of the associated selector.

2nd. The energization of a relay for establishing and maintaining theimpulse circuit, 4 the circuit of the said relay comprising the otherline conductor, and in each oifice by which the connection passes, a.similar relay; a this circuit remaining closed in each of the seriallyrelated selectors, until the final selector is directed to the calledline, the deener-' gization of these relays connecting up the talkingcircuit.

This invention permits the battery )feed the line conductor chosen forthe impulse shown in Fig. 2.

and supervisory, relays to be placed in the first selectors, and theincoming selectors (which are leastnin number) instead of in the finalselectors (which are greatest in number) as is actually the generalpractice, this effecting an economy desirable even in single ofiicetelephone system.

An application of the means of the present invention is particularlyadvantageous,

and is characterized in that, between two may be doubled and becomes.QX.

With this disposition, connections ma be established through a tandemofiice, wit out the use, neither of additional digits in the callingnumber, nor of register-sender equipment. A tandem office disposedaccording to this invention will have associated with each incomingselector, which establishes the connections local to the tandem oflice,a preselecting secondary switch which is always standing on an idletrunk leading to the following ofiice, and a switching arrangement whoseoperating position is determined by circuit by the preceding selector,the switching arrangement connecting up either the selector local or thesecondary switch to the incoming trunk.

The accompanying drawing represents, as an example only, three of thepreferred forms of realization of the invention.

In Fig. 1 is shown the circuit drawing of one form of realizing theinvention. The selectors circuits are not shown as they may be anv oneof the well known step. by step selectors. 4

In Fig. 2 is shown a second form of realization of the impulse circuit.

Fig. 3 is a diagram relative to the circuit showingthe application thecircuit of 5n referring to Fig. 1, when the calling station is connectedto a selector S,, impulsesare sent by the impulse sender 1, of any ofthe well known types which produce interru tions in the line circuit.The line relay 2 lies two windings, one 3 be ng connected between thebattery and the line conductor 4, the other 5 between earth and theother line conductor 6. The impulses sent over the line cause relay 2-toalternately attract and release its armature 7. Relay is shown as havingtwo windings, but it might have only one winding and the impulses sentover one line conductor only.

When the calling station is connected to relay 2, this relay energizesin series w th the station, and closes at 8 the followin circuit:battery-978--10earth. elay 10, upon energizing, closes the circuit:battery-relay 12-11'-13-and earth. Relay 12 energizes, prepares at 14 aholding circuit, and at 15 the impulsing circuit for relay 16.

When the impulse sender 1 is operated, at each interruption of the linecircuit rela .2 falls back, and closes at 17 the following circuit:battery-resistance 9contacts 7-- 1715--18'relay 16-and earth. Relay 16controls the operation of the selector, which is of the step by steptype, and

does not need to be described. The slow to release relay 10 does notfall back during the series of impulses.

After the transmission of the first digit of the called number, when thewipers 19 and 20 are brought to rest on an idle line, relay 21energizes, connects at 22 relay 12 to the line conductor 23, connects at24 the impulse circuit to the other line conductor 25, and o ens at 13the original holding circuit of re ay 12. As contact 22 is establishedbefore 13 is opened, relay 12 remains ener ized over the circuit: 19-inc conductor 23-and earth, in the selector S which in the presentexample is re resented as incoming selector in another 0 ce.

In the selector S relay 26 energizes in series with relay 12 of selectorS,, over the circuit: line. conductor 23--contact 55- wind ng of relay26contact 27and earth. The impulse circuit is connected to relay 28 overthe circuit: line conduct-or -contacts 30-,29-winding of relay 28andearth.

When the impulse sender is operated to send the second digit of thewanted number, at each interruption of the line circuit the circuit ofrelay 28 is closed by: batteryresistance 9-contacts 7--17--15-24 wiper20line conductor 25contacts 30--29-winding' of 28-and earth. Relay 28controls the operation of the selector 8,.

22--wiper As, explained for the selector S,, when the wipers of" S arebrought to rest on an idle line, relay 31 energizes, connects at 32 theearthed line conductor 33 to relays26 and 12 in series, and opens at 27their local holding circuit. At 34 the impulse circuit is connected toline conductor 35.

The following selector S is a hundreds selector in the same oilice as Sand S, is a line or final selector. S and S, have each an impulsingrelay indicated by 1628, since these relays have the same functions asrclays lti of S, and 28 of S and have besides a switching relayindicated by 2131,

since the function of these relays is the same as relay 21 of S, and 31of S ll hen the wipers of S, are brought to rest on the contacts of thewanted line, relay 21-31 energizes, opens the holding circuit of relay26 in S and relay 12 in S,. and in 37 and 38 connects up the wantedline, the impulse circuit being opened at 39.

In S,, relay 12 falls back and connects at 40 and 41 the battery feedrelay 42 to the line. In S relay 26 on falling back, opens at 44 thecircuit of the slow to release relay 43, which was energized when relay26 energized. Relay 43 does not fall back immediately when its circuitis opened and the circuit of relay 45 is closed at 46 and 47; relay 45energizes, and connects relay 49 to the line at contact 48. Relay 49energizes in series with relay 42, but on account of the high resistanceof the two windings relay 49, relay 42 is not energized. At 50, relay 49closes a new circuit for relay 43 before this relay has had time to fallback. Relay 45 on energizing connects at 51 and 52 the battery feedrelay 56 to the called side of the line; closes at 53 and 54 the talking circuit and opens at 30 and 55 the shunts around the condensers inseries with the lines conductors.

The talking circuit is now completely established.

When the called party takes down his receiver, relay 56 energizes andshort-circuits at 59 the high resistance winding of relay 49. Inselector 5,, relay 42 energizes in series with the low resistancewinding of relay 49, and in any well known manner operatesa subscribersmeter and provides supervision on the callin line.

It is not necessary to escribe the release of the connection, which iscontrolled by relay 10 of S, and 43 of S the'sc relays falling back atthe deenergization of 2 of S,

and 42 of S when the calling party hangs 2 ing used for the impulsecirehit being em-' vployed for making a. non-numerical selection, andfor holding the selectors in operated position. i

In the exam le represented, S, is a selector similar to and S, a finalselector.

The selector b, has two relays 16--28 and 21-31 the operation of whichis the same as described above. It has besides a reversing relay whichis, 01' is not energized according to the digit received by the selectorS Rela 60 on euer izin reverses at 3 y b P:

' lector, such as S relay 12 is connected in series with the lowerwinding of relay 67 in S over the circuit: battery-relay l2-lineconductor -wiper 64conductor 7 4contacts 6970--lower winding of relay 67and earth. Relay 67 energizes, closes at 71 a holding circuit by itsupperwinding, disconnects at 72 the lower winding of 68 from the 'lineconductor, and connects at 73 the line conductor 75 to the impulse relay16-28. Furthermore relay 67 prepares the connectin circuit for wipers 78and 79, at contacts '76 and 77. From this point on relays 16*28 and21--31 operate as described a eve.

2nd. The called digit is such as to cause the energization of relay 60.In this case, the relay 12 in the proceeding selector such as S isconnected in series with the lower winding of relay 68 by the circuit:conductor 75-contact 61--wiper 63-conductor 75- and contacts 8072.

Relay 68 energizes, closes a holdingcircnit by its upper winding at 81,disconnects at 70 the lower winding of relay 67 from conductor 74,connects at 82 the impulse relay 1628 to conductor 74-and prepares atcontacts 83 and 84 the connecting circuit for wipers 85 and 86.

,Fig. 3 is the diagram of a practical application of the circuit shownin Fig. 2 to a telephone oifice having a capacity for 4,000 lines. Thisoflice has only twoselecting stages; In the diagram, the first stage ofselection is represented by the selector S and the second stage by theline selector Sf, each of these selectors having twenty trunks perlevel, although the numbering system is decimal.

The line selector S, has access to 200 subscribers lines, but it onlyreceives two digits of the called number, the choice of the lines in oneor the other hundred to which it has access being determined by thepreceeding selector and which causes the operation or the non-operationof relay 60 (Fig. 2, S

of which two are entirel The first selector S, has accessto twenty oupsof line selectors S]. It receives two igits of the called number, thefirst digit causing the wipers to be brought to rest on the group oflines corres ruling to the called di 't. This roup of es comprises fivesu groups. he second digit. brings the wipers into contact with thefirst line inthe determined subgroup, and causes the excitation ifnecessary-of relay 60 in such a way as to release in this group tendifl'erent combinations.

The selection of an idle line in the chosen sub-group takes in the wellknown way.

The above described arrangement of selector S, can be applied to anytype of selector.

Fig. 4 represents an arrangement in which an incomin selector and anorgan which designed in t e following by the name tandem selector aregrouped together in. the same ofiice. This arrangement consists of threeparts independent, one from the other, and a t ird which cooperates withone or the-other of the first two. separately.

The two independent parts are the selector S, which for example may besimilar to the selector 8,, and the tandem switch CT.

The third part consists of the group of relays GR. The tandem switch CTis arranged so that its wipers are always at rest on an idle line.

The group represented by Fig. 4 is chosen by a selector such as S, andwhich maybe situated another ofiice); this grou can receive impulseseither over the con actor 75, or over the conductor 74. p

1st. The impulses come in over the con. ductor 74. In this case, relay87 ener izes in series with a relay, such as 12 (S, 1) by the circuit:earth-contacts 8889 winding of 87contacts 9091conductor 65-(relay 60energized) and relay 72to battery.

Relay 87 energizes, and remains energized over the circuit contacts92-9394earth. Relay 87 disconnects at 95 relay 96 from the conductor74;at 100, the circuit of relay 101 is closed, and this relay energizes.

lll)

Relay 101 connects at contacts 102 and gized)relay 12 S 64conductor 65(rela 60 not being enerig. 1)and battery.

Relay 97 is hel in operated position by contacts 1099394and earth; atcontact 90, relay 87 is disconnected from conductor 75, and at contact110, the impulse relay 16-28 is connected to conductor by 91--110-98-and 99.

Impulse relay 1628 of selector S, controls the operation of this switchas hereinbefore described. lVhen the wipers come to rest on an idleline, relay 2131 energizes and connects up the wipers 111 and 112 andthe following selector, to the line conductor 74 and by the contacts113114-, 9398,

and 91108.

Relay 96, being in series with conductor 74, remains energized by earthfrom the following selector. Relay 45 has the same functions as relay 45in selector S and is energized when the connection is established withthe called line.

Fig. 5 is a diagram of the application of the arrangement shown in Fig.4, in a telephone network having a tandem oflice Bt.

At Ed is re resented an oifice having access to the o co Ba, through thetandem ofiice Bt. Each oflice is supposed to have a capacity for 10,000lines, and that the subscribers numbers consists of 5 digits. The digitindicating ofiice Bt is the digit 5, that for oflice Ba is 6. When asubscriber in ofli'ce Bd calls the digit 5, the selector S takes an idleline to oflice Bt, but in this case relay 60 (5 Fig. 2) is not ener izedand the incoming selector S at ofiice t is used for establishing theconnection with a subscriber in otfice Bt. The four following digits ofthe called'number operate the local selectors in oflice Bt.

If the first digit of the wanted number is 6, selector S takes an idleline to ofiice B5" placed by an arrangement similar to the one composedof selector S and tandem switch CT in office Bt, and which would beoperated by an appropriate combination of dlgits in the calling number.It is quite clear that in this case the digit indicating one of theofiices Ba would correspond to the indicating digit of office Bt, whichin the case exposed above would be the digit 5.

One of the principal advantages of this arrangement is to have only onegroup of outgoing trunks between oflioe Ba and oflice Bt.

What I claim as my invention and desire to secure by Letters Patent is:

1. In an' automatic telephone 111, a callin line, an impulse sendingevioe in the circuit of the said line, a line relay serially relatedselector switches connected by two conductor trunk lines, a magnet ineach selector for controlling the setting of the said selector thecircuit of the magnet including a section of one of the conductors ofthe trunk line, an interrupter actuated by the line relay, and means,including the second conductor of the trunk line, for connecting thesaid section of the first conductor either to the said-interrupterduring the selection or to one of the conductors of the calling line atthe end of the selection.

2. In an automatic telephone system as claimed in claim 1, means forconnecting the second conductor of the trunk line to the secondconductor of the calling line.

3. In an automatic telephone stem a calling line, an impulse sendingevice in the circuit of the said line, a line relay, serially relatedselector switches connected b two conductor trunk lines, a magnet in eacselector for controlling the setting of the said selector, the circuitof the magnet including a section of one. of the conductors of the trunkline, an interrupter actuated by the line relay, a switching device forconnecting the said section of the first conductor either to the saidinterrupter during the selection or to one of the conductors of thecalling line at the end of the selection, and means including the secondconductor of the trunk line for controlling the position of the saidswitching device.

4. In a multi-ofiice automatic telephone system, a calling line, animpulse sending device in series with the said line, a line relay,serially related selector switches located in the several otlices of thenetwork and connected by two conductor trunk lines, a magnet in eachselector for controllin the setting of the said selector, thecircuit ofthe magnet including a section of one of the trunk line conductors, aninterrupter actuatecl by the line relay, a first switching device in theoriginating oflice for connecting the said section of the firstconduct/or either to the said interrupter during the selection or to oneof the conductors of the calling line at the end of the selection, meansin each of the other otfices for holding the serially related selectorsin operated position the said means being controlled by a switchingdevice and means including the second conductor of the trunk line forcontrolling the position of the latter switching devices and that of thefirst switching device located in the originatin oflice.

5. In an automatic telep one system, a

calling line, an im ulse device in series with the said ine, a linerelay, serially related selector switches connected by two conductortrunk lines, a magnet in each se- {oi-s, an interrupter actuated by theline re a at a switching device for connecting the section of the firstconductor either to the said interrupter during the selection or to oneof the conductors of the calling line at the end of the selection, aholding relay in the circuit of the second conductor of the trunk linefor operating the said switching device, means for ener zing the saidrelay before the selection ang means for opening the circuit of the saidrelay at the end 0 Q the selection.

circuit of the holding relay, means for closing the said interru ter atthe first energization of the line re ay and means for holding the saidinterru ter closed until the last de-energization of t e line relay. v

8. In an automatic telephone system as claimed inclaim 5, an interrupterin the cir cuit of the holding relay, means for closing thesaidinterrupterat the first energization of the line relay and for holdingit closed until the last de-energization of the said line relay, aswitchin device in each elector for prolonging the circuit ofthe holdingrelay to the following seriall' related selector and an interrupterdispose in the final selector for opening the circuit of the holdingrelay at the end of the selection. 9. In an automatic telephone s stem,a calling line, an im ulse sending evice in series with the sai line, aline relay, serially related selector switches connected b two conductortrunk lines, a magnet in eac selector for controlling the setting of thesaid selector, the circuit of the magnet including a section of one ofthe trunk line conductors, an interrupter actuated by the line relay, aswitching device for connecting the said section of the first conductoreither to the said interrupter during the selection or energization ofthe line relay and for. maintainin it closed until the lastde-energization 0 the said line relay, means for opening the otherinterrupter after the energizato the said interrupter during theselection tion of the holding relay, a locking circuit for the saidholding relay including an interrupter closed on the energization ofthis relay, a switching device in each selector for prolonging thecircuit of the holding relay to the following serially related fse-'lector and an interrupter disposed in the final selector for opemng thecircuit of the holding relay at the end of the selection.

10. In an automatic telephone system as claimed in claim 9 aninterrupter in the second conductor of the trunk line and controlled bythe holding relay for connecting this second trunk conductor to thecorresponding conductor of the callin line on the de-energization of thesaid re ay.

11. In a multi-oifice. automatic telephone system, a callingline, an.impulse sending device in series with the said line, a line relay,seriallyrelated selector switches located in the several ofiices of thenetwork and connected by two conductor trunk lines, a magnet in eachselector for controlling the setting of the said selector the circuit ofthe magnet including a section of one of the trunk line conductors, aninterrupter actuated by the line relay, a first switching device in theoriginating oflice for connecting the said section of thefiIStQOlldlICtOlfilthQI" or to oneof the conductors of the calling lineat the end of the selection, means in each of the other oflices forholdin the serially related selectors in 0 ate position the said meansbeing contro ed by a switch-- ing device, a first holding relay in 'theoriginating ofiice for controlling the position of the first switchingdevice, another holding relay in each other oflice for controlling theposition of the switching device in. its respective oflice the circuitof ,the holding relaysincluding the second trunk conductor, means forenergizing the first holding relay before the selection, means forenergizing each of the other holding ren0 .lay before the o eration ofthe selectors in the ofiice to which the considered relay is located andmeans for opening the circuit of the said relays at the end of theselection.

12. In an automatic telephone system as claimed in claim 11 means fordisconnecting the holding relays from the trunk line at the end of theselection.

' 13. In a multi-oflice automatic telephone 12c system, a calling-line,an impulse sending device in series with the said line a line relay,serially related selector switches lo cated in the several oflices ofthe network and connected by two conductor trunk lines, 12 a magnet ineach select'or for controlling the setting of the said selector thecircuit of the magnet including a section of one of the trunk lineconductors, an interrupter actuated by the line relay, a first switchingde- "9

